An ECU (Electronic Control Unit) is used as an electronic control device controlling a power train or the like mounted on a vehicle. For example, the ECU is activated in response to a turn-on operation of an ignition switch (or start switch) by a user (driver), and stopped in response to a turn-off operation thereof. If such an ignition switch is turned off and thereafter turned on while the vehicle is traveling, the power train having been stopped once is reactivated, which may cause regeneration of the drive torque which has been lost.
An example of the measures to prevent a shock due to the regenerated drive torque is disclosed in the abstract for example of Japanese Patent Laying-Open No. 2004-92623 (PTD 1). Specifically, it is disclosed, in the event of an engine stall while the vehicle is traveling, the engine is permitted to be started, on the condition that the throttle opening is a predetermined value or less, by turn-on of a starter relay.